Keyboard for musical instruments.



F. GLUTSAM. KEYBOARD FOR MUSICAL INSTRUMENTS.

APPLIOATION FILED DEG, 30, 1910.

- Patented Sept. 2, 1913.

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KEYBOARD FOB. MUSICAL INSTRUMENTS.

APPLIOATION FILED 11110.30, 1910.

1,072,311. Patented Sept. 2, 1913.

4 SHEETS-SHEET 2.

F. OLUTSAM.

KEYBOARD FOR MUSICAL INSTRUMENTS. APPLICATION FILED DEG. so, 1910.

1,072,31 1 Patented Sept. 2, 1913.

4 SHEETSSEEET 3.

F; GLUTSAM.

KEYBOARD FOR MUSICAL INSTRUMENTS.

APPLICATION FILED me. so, 1910.

Patented Sept. 2, 1913.

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311M Km Wouww COLUMBIA PLANOGRAPM c0 WASHINGTON, D, c.

UNITED STATES PATENT onnion.

FREDERICK CLUTSAM, OF BER-LIN, GERMANY, ASSIGNOR OF ONE-HALF TO ERNST JACOB, OF BERLIN, GERMANY.

KEYBOARD FOR MUSICAL INSTRUMENTS;

Specification of Letters Patent.

Patented Sept. 2, 1 913 Application filed December 30, 1910. Serial No. 600,095.

To all whom it may concern Be it known that I, Fnnonnion CLUTGAM, a subject of the King of England, residing at Berlin, in the Empire of Germany, have invented certain new and useful Improvements in Keyboards for Musical Instruments, of which the following is a specification.

This invention relates to improvements in piano keyboards and has particular reference to the keylevers and the mounting thereof.

The invention which will be more particularly described hereinafter is eminently suitable for keyboards for musical instruments such as pianofortes, organs, and the like.

According to this invention in a keyboard for an instrument the leverage of the keylever is varied during the operation of the latter. Thus, the leverage may be conveniently varied by mounting the key-levers in such a way that the position of the pivot point of the key-levers varies lengthwise of the key-levers during operation. In a preferred construction either the key-lever or the balance-rail supporting it, or both the key-lever and the balance-rail are formed with longitudinally curved contacting surfaces. In one modification the under side of the keylever is formed with longitudinal convex curvature, the curved surface being adapted to contact with a balance-rail having either a flat or conveXly curved surface. Further in levers according to the present invention one setof steadying pins may be arranged immediately at the back portion of the digitals in order to dlspense with guide pins in the rear portions of the keylevers. Other guide pins are as usual provided in the front of the key-levers.

Other features of this invention will be more readily understood from the following description taken in connection with the ac compa-nying drawings, the description being that of a keyboard for pianos.

Figure 1 is a side elevation, partly in section, of one form of key-lever and support;

Fig. 2 is a plan view of a portion of the key-lever shown in Fig. 1; Figs. 310 are side elevations, partly in section, of modified forms of key-lever and supports, and Fig. 11 is a plan view showing a particular arrangement of a keyboard, parts being broken away.

Referring to Figs. 1 and 2, a key-lever A 1s made the customary len th and moves over a balance-rail B. The balance-rail is carried on a bed or base C in the customary manner and in this particular example is provided with a flat surface. The portion of the key-lever in contact with the balance rail is curved as shown at D and has formed in it a slot E. The slot E has a restricted portion E which loosely surrounds a steadying pin F secured to the balance-rail B. The curvature at D can be so adjusted as to give the required amount of movement to each end of the key-lever A. When the front end of the key-lever, which may be conveniently termed a cradle-rocker keylever, is depressed for playing, it will be readily seen that at the commencement of the movement the leverage of the key-lever is at a maximum. Further, as the depression proceeds the leverage diminishes as 0wing to the movement of the curved surface of the keylever over the balancerail the fulcrum point moves toward the operator. As the key-lever rocks on the rail B said key-lever slides down on the pin F by reason of the pin opening E in said keylever. Thus at the commencement of the movement of the key-lever a relatively great leverage and small actuating force is employed resulting in a small movement of the hammeractuating mechanism while toward the end of the depression a reduced leverage effects a more rapid movement of the hammer-actuating mechanism. It is possible by giving suitable curvature to the key-lever and arranging the disposition of the curvature to enable both light and heavy hammers to be operated without the necessity for providing equalizing weights in the key-lever. The requisite freedom of movement required by the key-lever in its rolling motion over the balance-rail is provided for by the manner in which the key-leveris drilled to receive the steadying pin F. As shown in the illustrations the hole is larger at the bottom than at the top. The balance or pivot-point of the lever is the movable point of contact between the key-lever and the-balance-rail. The pin F does not act as a balance-pin but only as a steadying pin. It could equally well be employed near the end at the back of the key-lever as illustrated in Fig. 3, and still allow the necessary movement in the latter. Also two steadying pins F and F could beemployed as shown in Fig. l in addition to the customary guide pin F in the digital portion. In this construction, as also in the others shown herein, the aperture or apertures E through which the pins F pass, are of such dimension as will allow the keys to have sliding movement thereon when said keys rock on the balance rail. 7

If desired, the back portion of the keylever in its normal position may be slightly inclined downwardly from front to back so that the vertical movement of the back end involves as little horizontal movement as possible. For this purpose and other like purposes the portion of the key-lever and balance-rail which come into contact need not be substantially horizontal thus the balance-rail instead of being horizontal as in Figs. 1 and 3 may be inclined downward and backkvard as in Fig. 5. An advantage obtained fro-m this construction is that the end of the key-lever which operates the hammeractuating mechanism applies a force to the latter in a direction more nearly approximating the vertical than is the case with a key-lever pivoted about a fixed axis of rotation. V

Many modifications may be made in carrying the invention into effect, for instance, in place of the key-lever having a curved surface.contacting with the balance-rail, the balance-rail itself could be curved and the portion D of the lever straightas in Fig. 6. Again both the balance-rail and the keylever may be curved either or both having convex curvature as in Figs. 7, 8 and 9, or concave curvature as in Fig. 10, the relative curvature between the two, however, being so adjusted as to give the required motion to the key-lever.

In constructing a keyboard such as shown in Fig. 11, the custom isto mark on the uncut board the positions of the pilots G at the back and of the digitals A at the front; thereafter to mark off the position on the board of all the keyievers and when by measurement the balance-points of all the key-levers have been determined, the holes for the steadying and guide pins are board, the ivory is attached to the front and the whole board is cut up into keys. It is thus impossible to complete the boring or cutting for the steadying and guide pins until the measurements and proportions of the vari ous parts of the Keyboard are known. Owing to the shrinkage or other deformation which takes place in the keyboard and in the bed or balance-rails, etc., on which the keyboard is mounted (consequent on the use of wood and glue) it is necessary to allow certain parts to assume their final shape before even the marking out can be completed. Thus another object of this invention is to enable the manufacture and mounting of keyboards to be commenced and proceeded with to a considerable extent before the actual measurements of the rear portion have been marked out; the practical object being to enable the manufacturer to turn out partially completed and mounted keyboards which can be kept in stock and afterward cut to suit requirements. That is to say allow the necessary shrinkage to take place, arrange the guide pins, apply the ivory to the digitals and if need be partly cut the digitals before the dimensions of the rear portions are known.

In an ordinary keyboard, when the exact position of a particular keyle'ver has been marked out, a line is drawn from the pilot point to the center of the front of the digital and the usual steadying pin has to be placed approximately on this line on the balancerail. In a preferred construction according to this invention, however, the steadying pins need not be arranged at the balance-rail but will be, in the case of two sets of guide pins, arranged as shown in Fig. 9. That is to say the steadying pin F in each lever is arranged immediately at the back of the digital portion and is not secured to the balance-rail. The position of the steadying pins can thus be entirely independent of the conformation of the rear portions of the keylevers. The digital portions being already standardized it is therefore possible to prepare the'uncut keyboard and the supports therefor including the bed or balance-rail, etc., cut the holes as described, then attach the ivory and if desired partially cut out the digital portions of the keys. Keyboards in this stage of completion can then be kept in stock. In other words the boring necessary for the guide pins and the completion of the digital portions can all be effected independently of the setting out of the rear portions of the key-levers.

If desired, a guide pin F may be employed at the rear end of each key-lever the necessary hole being bored when the position of theback scale is known. Such a guide pin is shown in dotted lines in Fig. 9.

In keyboards having the rear portions of the key-levers fanned, according to this invention there is employed a balance-rail which is not only curved at its upper surface in transverse section as shown in Figs. 7, 8, 9 and 10 but is also bent or curved as to the whole of its length in such a way as to bring the axis of surface curvature at each key-lever substantially at right-angles to the line joining the ends of that key-lever. This is indicated by the reference letter D the part thus indicated being either the balance rail or the curved portion of the key-lever or both, as another way of carrying this invention into effect is to cut the curved portions of the key-levers not straight across the keyboard but substantially in the form of an are extending across the keyboardin such a way that the axis of curvature of the contacting surface of each key-lever is at rightangles to the line joining the ends of that key-lever.

It is obvious that modifications other than those herein referred to may be made in carrying the invention into effect provided the spirit of the invention is not departed from.

What I claim as my invention and desire to'secure by Letters Patent is 1. A keyboard for musical instruments comprising a key-lever, a support therefor, and co-acting surfaces on said key-lever and support in rocking engagement with one another to change the point of contact longitudinally of the key-lever as said key-lever is operated.

A keyboard for musical instruments comprising a key lever support having an inclined surface, a key lever having a surface to coact with said inclined surface, said surfaces being in rocking engagement with one another to change the point of contact longitudinally of the key lever as said key lever is operated.

3. A keyboard for musical instruments comprising a support, and a key-lever having a longitudinally inclined curved surface arranged in contact therewith to change the point of contact longitudinally as the keylever is operated, substantially as described.

4:. A keyboard for musical instruments comprising a support, a keylever having a longitudinally inclined curved surface in contact with the support, and means for steadying the key-lever on the support and at the same time permitting the key-lever to change its point of contact longitudinally as same is operated, substantially as described.

5. A keyboard for musical instruments comprising a support, a key-lever having a longitudinally inclined curved surface in contact with the support, and a steadying pin; said key-lever being provided with a recess for receiving the steadying pin whereby the key-lever is permitted to roll on the support and change its point of contact therewith longitudinally as it is operated, substantially as described.

6. A keyboard for musical instruments comprising a support, a key-lever having a longitudinally inclined curved surface in contact with the support, and a steadying pin projecting from the support; said keylever being provided with a recess for receiving the steadying pin whereby the keylever is permitted to roll on the support and change its point of contact therewith longitudinally as it is operated, substantially as described.

7. A keyboard for musical instruments comprising a support, a key-lever having a longitudinally inclined curved surface in contact with the support, a steadying pin projecting from the support' said key-lever l eing provided with a recess for receiving the pin whereby the key-lever is permitted to change its point of contact longitudinally as it is operated; and a guide for the keylever, substantially as described.

8. A keyboard for musical instruments comprising a base, a balance-rail on the base, a key-lever having a longitudinally inclined curved surface in contact with the balance-rail, a steadying pin projecting from the balance-rail, said key-lever being provided with a recess for receiving the steadying pin whereby the key-lever is permitted to roll on the balance-rail and change its point of contact therewith longitudinally as it is operated, and a guide pin on the base for guiding the key-lever, substantially as described.

9. A keyboard for musical instruments comprising a base, a balance-rail on the base, the balance-rail being transversely inclined downwardly, and a key-lever having a longitudinally inclined curved surface arranged in contact with said inclined surface of the balance-rail to change the point of contact longitudinally as the key-lever is operated, substantially as described.

10. A keyboard for musical instruments 9 comprising a base, a balance-rail on the base, said balancerail having a transversely and downwardly inclined surface, a steadying pin projecting from the balance-rail, said key-lever being provided with a recess for receiving the steadying pin, and a guide pin projecting from the base for guiding the key-lever, substantially as described.

11. A keyboard for musical instruments comprising a base, a balance-rail on the base, said balance-rail having a transversely curved surface, a key-lever having a longitudinally inclined curved surface in contact with the curved surface of the balance-rail, a steadying pin projecting from the balancerail, said key-lever being provided with a re cess for receiving the steadying pin, and a guide pin projecting from the base for guiding the key-lever, substantially as described.

12. A keyboard for musical instruments comprising a base, a balance-rail on the base, said balancerail having a transversely curved surface, a key-lever having a longitudinally inclined curved surface in contact with the curved surface of the balancerail, a steadying pin projecting from the base, said key-lever being provided with a recess for receiving the steadying pin, and a guide pin projecting from the base for guiding the key-lever, substantially as described.

13. A keyboard for musical instruments comprising a base, a balance-rail on the base, said balance-rail having a transversely curved surface, a key-lever having a longitudinally inclined surface in contact with the curved surface of the balance-rail, a steadying pin projecting from the balance-rail; said keylever provided with a recess to receive the steadying pin whereby the key-lever is permitted to roll on the balance-rail and change its point of contact therewith longitudinally as it is operated, and a guiding pin projecting from the base at each side of the balancerail, said key-lever being provided with recesses for reoeivin the Quidin oins wherehr the he -lever is uided suhstantiall as a a described.

In testimony whereof I have slgned my name to this specification in the presence of 15 Copies of this patent may be obtained for five cents 'each, by addressing the Commissioner of Patents.

Washington, D. C. I 

